Can a landlord let you stay on her property without any signed agreement?

When I moved in it was verbally agreed on a certain amount. The landlady agreed that I can stay on her property and that I would pay her on a later stage as I wasn't working at that time but studied. After six months she told me that she could not draw up an agreement because I was in arrears knowing that she allowed me to stay on her property. I am working now and I am able to pay her the full amount of which I owe but nothing have been put on paper and now she is demanding me to pay electricity and water irrespective of me making use of the amount she charging me for electricity and water. She has two other tenants on her property and I have to pay the exact amount for electricity and water that they are paying. I have my own wendy house on her property. Please advice.